Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 49: 2D Materials: Electronic Structure and Exitations III (joint session O/HL/TT)
HL 49.2: Vortrag
Donnerstag, 20. März 2025, 10:45–11:00, H11
Superlattice engineering in graphene and 1T-NbSe2 heterostructures — •Keda Jin1,2, Lennart Klebl3, Junting Zhao1,2, Tobias Wichmann1,5, F. Stefan Tautz1,5, Felix Lüpke1, Dante Kennes4, Jose Martinez-Castro1,2, and Markus Ternes1,2 — 1Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany — 2Institut für Experimentalphysik II B, RWTH Aachen, 52074 Aachen, Germany — 3I. Institute for Theoretical Physics, Universität Hamburg, 22607 Hamburg, Germany — 4Institut für Theorie der statistischen Physik, RWTH Aachen, 52074 Aachen — 5Institut für Experimentalphysik IV A, RWTH Aachen, 52074 Aachen, Germany
Superlattice engineering has become a major branch of condensed matter research, not at least due to the variety of exotic states observed twisted in van der Waals heterostructures. We here present a new method to periodically modulate graphene by stacking it on 1T/2H-NbSe2. By tuning the twist angle, we realized two near-commensurate superlattices: √3×√3 and 2× 2 aligned with the charge density wave (CDW) of 1T-NbSe2. Using scanning tunnelling microscopy, we visualized local stacking configurations for these two superlattices. We applied a newly developed symmetry analysis method to track rotational symmetry breaking as a function of bias. In the 2× 2 superlattice, C3 rotational symmetry was preserved. However, in the √3×√3, a strong strip phase occurs. This symmetry breaking is explained by our tight-binding model. Our findings highlight a mechanism for superlattice-induced symmetry breaking that hints towards exotic states of matter.
Keywords: graphene; scanning tunneling microscopy; superlattice engineering